package cn.lsc.filter;

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.List;

@Component
@Slf4j
public class LoginCheckFilter implements GlobalFilter,Ordered {

    // 执行此filter的业务方法
    // exchange：上下文对象，chain：filter的调用链对象
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //获取token
        ServerHttpRequest request = exchange.getRequest();
        String path = request.getURI().getPath();
        //判断请求路径是否包含token和register
        if(!path.endsWith("login") && !path.endsWith("register") ){
            List<String> token = request.getHeaders().get("token");
            log.info(""+token);
            log.info("当前用户的请求路径：{}",path);
            // 如果token为null，说明没有登录，那么响应nologin
            if(token==null){
                // 1.响应对象
                ServerHttpResponse response = exchange.getResponse();
                // 2.构建错误结果
                HashMap<String,Object> data = new HashMap<>();
                // 3.设置响应信息
                data.put("code", 401);
                data.put("success", false);
                data.put("message","登录校验失败，请重新登录！");

                DataBuffer buffer = null;
                try {
                    //  4.转换参数，包装buffer对象
                    // 4.1.将数据转换为JSON，再转换为byte数组
                    byte[] bytes = JSON.toJSONString(data).getBytes("utf-8");
                    // 4.2.将byte数组包装到DataBuffer对象中，用于响应给浏览器，构建响应内容
                    buffer = response.bufferFactory().wrap(bytes);

                    // 5.设置完成响应，不会继续执行后面的filter
                    // 5.1.设置响应状态为401
                    response.setStatusCode(HttpStatus.UNAUTHORIZED);
                    // 5.2.设置响应格式
                    response.getHeaders().add("Content-Type","application/json;charset=UTF-8");
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                // 6.把结果写给客户端
                return response.writeWith(Mono.just(buffer));
            }

        }

        // 继续执行下一个filter
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
